Leptospirosis is a bacterial disease that can enter two ways through your dog's body. It can either enter through your dog's skin, or can enter by water indigestion with the an affected animal's urine (usually rat). Your dog has natural antibodies for it, but it may damage your dog's kidneys and liver. You can tell if your dog has it if he/she vomits for over 24 hours. You can get your dog antibiotic treatment from the vet when Leptospirosis occurs, but you can prevent it by giving your dog the D.H.L.P.P vaccine.